A conventional stapler generally includes a nose connected to a front end of the barrel of the stapler and a handle is connected to the barrel so as to be connected to a hose through which pressurized air introduced to eject nails or staples from the nose. A top plate is secured to the nose so as to define a passage for guiding nails or staples. In order to easily remove deformed nails or staples stock in the passage, the top plate is connected to the nose by screws. However, it requires screw drivers to unscrewed the screws when removing the top plate from the nose. This is not convenient for the users who cannot find a screw driver to unscrew the screws. Some manufacturers use a fastening device including a U-shaped member for hooking the top plate in position on the nose. Nevertheless, the U-shaped member tends to be deformed because of high stress concentration at bending portions. Once the U-shaped member is deformed, the gap between the top plate and the nose becomes wider and this could lead the nails or staples to undesired directions.
The present invention intends to provide a fastening device that uses an enclosed loop having two curved sections for providing proper flexibility so as to reduce any potential deformation of the loop.